Answer from cs61c-eq (Nicholas Hwang 16732453) for Question 2
b and c are true. When blocks are coalesced, neighbors of a block in the process of being freed will be combined into one block to make a single, larger block of memory to be freed. At most, the change will go from having two free blocks of memory who are both neighbors of a block being freed to one block of memory that combines all three (reducing the number of free blocks by one). It is also possible that coalescing will keep the number of free blocks constant.